f

foo.c

#include "libbar.h"
int main() {
    bar();
    return 0;
}

libbar.c

#include <stdio.h>
#include "libbaz.h"
void bar() {
    printf("bar\n");
    baz();
}

libbar.h

void bar();

libbaz.c

#include <math.h>
#include <stdio.h>
void baz() {
    printf("baz, sin(pi/2)=%lf\n", sin(M_PI / 2.0));
}

libbaz.h

void baz();

Makefile

all: libbaz.so libbar.so foo

# libbaz depends on libm
libbaz.so: libbaz.h libbaz.c
	gcc -o $@ -shared -fPIC -lm $^

# libbar depends on libbaz
libbar.so: libbar.h libbar.c
	gcc -o $@ -L. -Wl,-rpath=. -lbaz -shared -fPIC $^

# foo depends on libbar
foo: foo.c
	gcc -o $@ -L. -Wl,-rpath=. -lbar $^

.PHONY: clean
clean:
	rm -f libbaz.so libbar.so foo

patch

diff --git a/Makefile b/Makefile
index 2d20a1c..d7a6bf3 100644
--- a/Makefile
+++ b/Makefile
@@ -11,7 +11,12 @@ CXXFLAGS := $(CXXFLAGS) -Wall -Werror -Wextra -fPIC
 MODULE_NAME := netkit
 
 INCLUDE :=
-LIBS := ./deps/logger/liblogger.a ./deps/threadpool/cpp/libthreadpool.a -lpthread
+LDFLAGS := -L./deps/logger \
+           -L./deps/threadpool/cpp \
+           -Wl,-rpath=./deps/logger \
+           -Wl,-rpath=./deps/threadpool/cpp \
+           -llogger \
+           -lthreadpool
 
 OBJS := $(patsubst %.cpp, %.o, $(wildcard *.cpp))
 
@@ -33,7 +38,7 @@ lib$(MODULE_NAME).a: $(OBJS) | pre-process
 	$(AR) rc $@ $^
 
 lib$(MODULE_NAME).so: $(OBJS) | pre-process
-	$(CXX) -shared -o $@ $^ $(LIBS)
+	$(CXX) -shared -o $@ $(LDFLAGS) $^
 
 .cpp.o:
 	$(CXX) $(CXXFLAGS) $(INCLUDE) -c $< -o $@